I have the same issues with at least 2 dozen spam messages a day. The subject filter does not wotk,because I receive the same Email from the subject I was supposed to filter the next day. Email blocking does not work because the Email address of the Spam is invalid I have sent over a 1,000 email@example.com to Verizon. I have yet to receive a reply. Verizon does not seem to care about this problem.
Welcome to the forums. You're talking to other customers here.
This is a reoccurring questions on these boards, as Verizon's spam filter is not great. A quick search for "spam" will yield plenty of spam discussions. Short story; the best thing you can do is switch to an email service that has good spam filters. gmail is a popular option and can be used with Verizon.net email. Search the archives for details.
Verizon provides perhaps the poorest spam blocking in the industry. I use spam blocker and I used filters until Verizon allowed no more, and I send a dozen spam emails to Verizon spam not detected email daily, Clearly Verizon has no intention to make this a priority. I will probably stop using Verizon for email, internet, phone, and television when contract is up. That is how maddening this is for me. In the meantime I suggest you find non-Verizon email account. I do know spam handling is many times better by both yahoo and gmail and probably every other provider.